Dynamometer



J. ASCARR I May 28, 1935.

'DYNAMOMETEB Filed June 29, 1951 Sheets-Sheb l mm S. am.

I NVENTOR J.,4. CARR ATTORNEY 2 sheets-sheet 2 uw S f TV1 f v Fl Y A mw om j @um J. A. CARR May 28, 1935.

Patented May 2&8, 1935A Y AUNITEDjs'lAiEs Y n l YmzNAMoME'rliin James A. Carr, Maplewood;` N. I., assgnorto Bell Telephone Laboratories, `Incorporated, New York, N; Y., acorporation of NewYork npplication June 39,' V1931, serial No. 547,507

use for measuring the tension in wire spans and the like.

Injdynamom ers heretofore used for measur- 5r ing the tension, in wire spans,y hook members are provided'at the ends of, a bar for engaging and retaining the wire in place during the operation of a third member tending to deviate the wire ,g in a direction at right angles to itslefngth, aA

' gage being provided vfor recording thek move-'f v mounting blockhaving a .jaw memberv IIL and ment ofthe latter member in terms 'ofV the tension in therwires.

- While these dynamometers ,havebeen found n, satisfactoryV for the measurement vof .wires of l*relatively large diameters' they arerinaccurate for'the tension measurement of small wires owing to the amount of friction developed at the hooks with wire under tension. Kinks or bends y in the wires also vary the force required 'tov pushfthe wire out of line and this also introduces other serious errors in theV tension measure-A stud-5 0, in turn-journaled on brackets I2 and" I3. A substantially v shaped spring iI'Ijshownv ment of ne wires. Y

Inv the dynamometer` of Ythis invention these errorsare4 avoided by the provision of means whereby the tension of the wire is transferred to a. spring mechanism acting in line parallel to the general direction of the wire, lthus avoiding the errors due to bends in the wire and to the friction of the wire with the actuating parts of the dynamometer mechanism.v

This is accomplished by providing pairs of clamping devices for positively gripping the wire at two places a small distance apart. Arpair of springs are attached at one end to one of the clamping devices and the other ends of these springs are attached to a movable cross bar slidably mounted on a guiding member which also supports the other clamping device. A link in the form of a cam connects the'movable clamping device to the cross bar and this cam is operable for tensioning the springs for trans'- ferring the tension in the wire to the dynamometer mechanism. A gage which is carried by the cross `bar has its actuating member disposed in operable relation with a rod mounted on the stationary block, this gage being operable for indicating theY movement of this cross bar and thereby the elongation of the springs in Erms of the tension in the wire.

Other features of the invention and advantages will appear from the following `description and by the claims lappended thereto, reference being had to the accompanying drawings in which:

Fig. 1 is a front assembly view showing the springs tensioning mechanism and the wire This vinvention relates v"to" dynamometers for.

2 claims. (cl. 265-1) clamping devices in normal non-operated lpo`l sition; l Fig. 2 isa front assembly view showing the springs tensioning mechanism and` thek wire clamping devices in the operated position;

Fig. ,3 is a side view of Fig. l2; v

Fig. 4 is an end View; and Y Y Fig. 5V is a partial view in section showing the gage actuating mechanism. 'Y f Through the several figures, I -indicates a brackets I2 and I3 integrally formed therewith. 'I he bracket I3V is-provided with a rectangular opening Il,-in which an L-shaped jaw' member I is mounted forfmovement towardl jaw member Il under control of a -manually operable cam I6. Jaw member I5 is guided in its gripping n movement toward` jaw member II by a-stud 5 0 engaging aV slot 6I and bythe sidewalls ,of aperture 4I4y engaging'the jaw as shown in Figs. 2 and 3. This Ycam is pivotallymounted on, a

in Figs. 1 and 2 is provided for retracting the jaw member I5 to normal upon the movement of cam I6 fromA position shown in Fig. 2 to position shown in Fig. 1, the movement of cam I6 in position shown in Fig. 2 being effective to clamp the wire W between the jaw members II and I5. s Y Y A The mounting block I0 has two screw threaded holes I8, as shown in Fig. 5, provided for receiving similar threaded plugs I9. Y These plugs have each an enlarged threaded portion for engagement with the ends of springs and 2 l. On the block Ill is mounted a pair of bars 22 and 23, which are securely held thereon by a number of screws, such as 24. These bars extend in parallel relation with respect to the longitudinal axes of springs 2,0 and 2I and on them is slidably mounted a cross bar 25. This bar, like the block I0, has t'wo counter-` sunk holes for receiving the plugs 26 and 2I shown in Figs. l, 2 and l and in sectional View in Fig. 5,

These plugs are securely held therein by nut formed with lplug 21 in engageablerelation with the actuating plunger 33 of gage 3D.

On the free ends of bars 22 and 23 there is slidably mounted a blockv 34 having a jaw member 36 and a rectangularly shaped opening 35 -for receiving a movable jaw member 31 arranged to be actuated by a manuallyoperable camming member 38 rotatably mounted on a stud 50'.

- Jaw member V37 is guided in its gripping movement toward jawfmember 36 by a stud 62 engaging a slot 63 Vand the side walls of aperturer35, as shown in Figs. 2 and 3.

retractingfL this jaw member. to `normal upon a movement of cam 38, the movement'oi this cam being effective to Vclamp the wire ,W'betweenethe jaw members 35 and 37.

The block 34 carries an inwardly yextending bracket 42 on which a manually operated cam 4 3" which may be of twoV pieces as shown in Fig. 1 or of a'siriglepiece as shown in Fig. 2,V is placed'be-v tweenl the pairs of jaw members "I i-I5 and 36-31 and -the'fcamming'members i3 and 38 moved from'bposition shown in'Fi'g. 1 to position' shownvin Fig. 2V for securing rthe wire to `the blocks I and/34. The cam 43 is thengmoved from position shown in-Fig. l to position shown in Fig.'2`for tensioning'the springs 2B and 2 l, thisV cam. remaining in" 'the'v operated position against the tension ofthe springs upon'reaching the radial portion at the end of the cam. The tensioningoffsprings 2D and 2| is effective to transferthe tension' in-the wire to the springs owing tothe non-yieldablelink between the cross b ar Y V2,002,977'v .i

This cam is pivota'llyv mounted on'brackets 39 and 40 formed integrally with the block 34 and a spring'4rl is providedfon 25 and the block 34 offered by the cam 43, The cross bar 25 Yandthe block 34 connected thereto are caused to slide along the bars 22-23 until the tension of the springs equalizes the tension in the wire. The movement Yof cross bar 25 and block 34 with respect to block l0 is effective to cause the operation of the gage 30 due to the engagement of rod 32 with the actuating plunger 33 of gage v3l), thusv translating the movement of the cross bar 25'relative to block l and thereby the tension inthe springs 20-2l in terms of the tension in the Wire.

What `is claimed is:

1 v1. in a device of the kind described, a frame .having'a fixed ,clamping member and a movable clarlupingl membenza block slidable upon said ,frame betweenthe vclamping members, spring Y means between the fixed clamping member and said block, said 'springmeans being anchored at its'ends to .said xed clamping member and said blpck respectively, .a gauge for indicating the tension of said spring. means," a. tensioning cam lever` connecting saidislidable block a'nd movable clamping member for drawing themV toward each other jagainst the tension of said spring means and thereby transferring the tension .inthe specimen held by'the clamping members 'to said spring means.

2. .Infa wire testing dynamometer, a clamping device, guiding members carriedlby said device,

Vanother clamping device s lidably rmounted on said members, a movable cross bar slidably arranged on said guiding members, springs interconnecting the first imention'edclmping device with said crossA bar,4 a tensioning mechanism` for said springs interconnecting thesecond mentioned device with saidi cross 'bar andoperable to move said cross-gbaria'nd' second' clamping device together a Vpredetern'iined distancefor .transferring v the tension of the wire to said springs, and a gage for'indicating the movement of lsaid cross bar and the second mentioned clamping device away from the rst mentioned device. V

' UJ'AMES A. CARR... 

